http://www.informationclearinghouse.inf ... le6480.htmCARL CAMERON, FOX NEWS CORRESPONDENT (voice-over): The company is Comverse Infosys, a subsidiary of an Israeli-run private telecommunications firm, with offices throughout the U.S. It provides wiretapping equipment for law enforcement. Here's how wiretapping works in the U.S.

Every time you make a call, it passes through the nation's elaborate network of switchers and routers run by the phone companies. Custom computers and software, made by companies like Comverse, are tied into that network to intercept, record and store the wiretapped calls, and at the same time transmit them to investigators.

The manufacturers have continuing access to the computers so they can service them and keep them free of glitches. This process was authorized by the 1994 Communications Assistance for Law Enforcement Act, or CALEA. Senior government officials have now told Fox News that while CALEA made wiretapping easier, it has led to a system that is seriously vulnerable to compromise, and may have undermined the whole wiretapping system.

Indeed, Fox News has learned that Attorney General John Ashcroft and FBI Director Robert Mueller were both warned Oct. 18 in a hand-delivered letter from 15 local, state and federal law enforcement officials, who complained that "law enforcement's current electronic surveillance capabilities are less effective today than they were at the time CALEA was enacted."

Congress insists the equipment it installs is secure. But the complaint about this system is that the wiretap computer programs made by Comverse have, in effect, a back door through which wiretaps themselves can be intercepted by unauthorized parties.